<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
    <script src="https://cdn.bootcss.com/jquery/3.3.1/jquery.js"></script>
</head>
<body>

<h2>Click</h2>

<div class="app">
    <input v-model="name"   type="text" class="name">
    <h1>{{name}}</h1>
    <button class="ajax" @click="get">ajax</button>
    <ul>
        <li v-for="user in users">
            {{user}}
        </li>
    </ul>
    <img v-if="users.length<=0" style="width: 200px;"
            src="https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1538314253949&di=0308db1022c172d53041d105b8e01ddb&imgtype=0&src=http%3A%2F%2Fimg.zcool.cn%2Fcommunity%2F017ebd58d921baa801219c775b6f3b.gif">
</div>
</body>
<script>

    $('h2').click(function () {
        var m = mix(20, 30);
        alert(m);
    })

    function mix(n ,m) {
        return n+m;
    }

    var app=new Vue({
        el:'.app',

        data:{
            name:'aaa',
            users:[],
        },

        mounted: function(){
            this.get();
        },

       methods:{
            get:function () {
                var that=this
                $.ajax(
                    {
                        url:"http://api.coindog.com/api/v1/symbols",
                        success:function (jj) {
                            that.users=jj;
                        }
                    }
                )

            }
       }

    })

    //

</script>
</html>